“Anyone who stops learning is old, whether at 20 or 80,” American entrepreneur Henry Ford once said. “Anyone who keeps learning stays young.”

There’s something to that, a new study says.

People who engage in a lifetime pursuit of learning have a lower risk of Alzheimer’s disease, as well as slower brain aging, researchers report in the journal Neurology.

People with the highest amount of lifelong learning had onset of Alzheimer’s delayed by five years, compared to those with the lowest amount, researchers found.

They also developed mild cognitive impairment seven years later, the study showed.

Overall, higher scores in lifetime enrichment were linked to a 38% lower risk of Alzheimer’s and a 36% lower risk of mild cognitive impairment.

“Our study looked at cognitive enrichment from childhood to later life, focusing on activities and resources that stimulate the mind,” lead researcher Andrea Zammit, an assistant professor of psychiatry and behavioral sciences at Rush University Medical Center in Chicago, said in a news release.

“Our findings suggest that cognitive health in later life is strongly influenced by lifelong exposure to intellectually stimulating environments,” she said.

For the new study, researchers tracked more than 1,900 dementia-free people with an average age of 80 for about eight years.

The participants filled out surveys about their brainpower and learning at different stages of their lives:

• Early enrichment before age 18 focused on being read to and reading books; having newspapers and atlases in the home; and studying a foreign language for more than five years.

• Middle-age enrichment included income level at age 40; household resources like magazine subscriptions or library cards; and frequency of visits to museums or libraries.

• Later-life enrichment, starting at an average age of 80, included reading, writing, playing games and total retirement income.

During the study, 551 people developed Alzheimer’s and 719 developed mild cognitive impairment, a precursor to dementia.

Among those with the highest level of enrichment throughout their lives, 21% developed Alzheimer’s.

By comparison, 34% of those with the lowest level of enrichment developed Alzheimer’s, researchers found.

People with the highest lifetime enrichment developed Alzheimer’s at age 94 on average, compared to 88 for those with the lowest.

Likewise, those with highest lifetime enrichment developed mild cognitive impairment at 85, compared to 78 for those with the lowest.

People with higher lifelong learning retained their memory and thinking skills even if they experienced early brain changes linked to Alzheimer’s, researchers found.

“Our findings are encouraging, suggesting that consistently engaging in a variety of mentally stimulating activities throughout life may make a difference in cognition,” Zammit said. “Public investments that expand access to enriching environments, like libraries and early education programs designed to spark a lifelong love of learning, may help reduce the incidence of dementia.”